Method and apparatus for making dental crowns



Sept. 2 1924.

J. M. FLANIGAN METHOD AND APPARATUS FOR MAKING DENTAL BROWNS Filed Dec. 2, 1921 ATTORNEYS 4 WITNESSES Patented Sept. 2, 1924.

JOSEPH MICHAEL FLANIGAN, or snAMoxIN, PENNSYLVANIA.

METHOD AND APPARATUS FOR MAKING DENTALQROWN S.

Application filed December 2, 1921. Serial No. 519,489.

To all iulzom it may concern:

Be it known that I, JOSEPH M. FLANIGAN,

a citizen of the United States, and a resident of Shamokin, in the coiuity of Northumberland and State. of Pennsylvania, have in vented a new and Improved Method and Apparatus for Making Dental Crowns, of which the following is a. full, clear, and exact description. r

This invention relates to a method and apparatus for making dental crowns. An object of the invention resides in the provision of means whereby crowns for teeth of gold or other metal may be very quickly and easily constructed with a minimum number of operations, thereby saving awgreat deal of time. and. labor and rendering the operation more economical than has hitherto been the case.

Another object. resides in the provision of means whereby a. very true and exact crown can be made of a. tooth of any configuration or articulation.

A'further object resides in the provision of a. method in. which the. steps are reduced to a. minimum and in which the ease; of manipulation of the various steps and processes is considerably enhanced.

A still further object resides in the parti cular sequence of operations and in the arrangement. and construction of the "parts hereinafter described and claimed and shown in the accompanyingdrawings.

The invention is shown in the drawing of which a I Figure ljis a perspective View of an impression of a. bite of the. contour of certain teeth for which it may be desired to make a crown. I i 4o Figure- 2 is a transverse section taken through the device. shown in Fig. 1. I Figure 3 is a View of a metal tooth moulded and showing the matrix in position.

Figure 4 is a. side view of a metal tooth with a. gold crown placed thereover but not formed thereon. v

Figure 5 shows the apparatus used toshape. or form the gold crown in accordance with the. contour of the tooth.

Figure 6 is an enlarged detail View of the apparatus shown in Fig. 5.

Figure 7 is a View showing the metal tooth with. the. crown shaped thereon.

Figure 8 is a section of the crown removed from the metal tooth.

The process and the apparatus set forth r in the drawings and hereinafterdescribed are'preferred applications of my invention but various changes may be made in the manner of performing or carrying on the operation and in the construction andarrangement of the parts without departing from the general spirit of the invention as described and set forth herein. I

In the first steptaken to produce agold crown for any givenztooth, it is necessary for any person familiar with the operation of taking impressionsof teeth-toplace in the patients mouth adevice which may be a mold receptacle, such as 1, having a handle 2. Within this receptacle 1 is placed a plastic material ofany desired character in which is formed an outline of the contour of certainteeth when the patient sinks his teeth into the plastic material 3. Assuming that it is desired'to produce. a crown of gold or other material for one of-the teeth of which impressions have thus been obtained, the first'step; is to place over the impression of that particular tootha m trix at, which as shown is in the form of a shell of any desired metal, but which can be 'madein the form of' a sheet and then bent around to form a cylindrical 'shell. The ends of this shell or sheet may be lapped over each other or may be made of exactly the right. size. Furthermore, instead of being made -in a sheet the shell may be made in cylindrical form with the ends suitably connected or welded togetherinto a cylinder of the proper diameter. 1 The ends of this matrix or shell need not be connected .or welded but may be placed with their edges abuttingand then this joint mayv be sealed by the goldwhich is later placed around the matrix. This cylinder or shell or matrix is placed over the impression of the tooth and around it is placed a composition ofmetahsuch as 5, and clay 6, to seal the shell in position. After this shell or matrix is firmly fixed in position, molten metal 7 of any suitable composition is poured into the matrix and fills the impression of the tooth as well as the space within the shell. There is, therefore,

formed in the impression space a model or duplicate 8 of the tooth for which it is desired to produce a crown. The matrix, with the metal tooth, is then removed from the impression or mold and is in the form shown in Fig. 3. The matrix is then rethereon in accordance with the contou-rofthetooth. The portion 7 of the tooth, which I may call the stem portion, is then placed in a-suitable bore such as 10 in a swaging block 11. The stem is so placed within the bore that the tooth portion 8 and the gold crown 9 extend into a receptacle 12. This receptacle 12 is of any suitable material, preferably metal, and contains a mass of some resilient cushioning material 13, which is preferably wet cotton. This receptaclel2 for convenience may be disposed in a suitable recess in the top of a large block or support 14 which may act in the nature of an anvil. The size of the opening of the receptacle 12 is substantially the same as the outer diameter, of the swagingblock 11, and, therefore, to properly shape the gold crown on to the tooth 8 it is merely necessary to tap or strike the swaging block 11 with any suitable instrument, such as a hammer 15, a fewtimes, forcing the swag'ing block With the tooth and the crown into the receptacle 12. The pressure of the cotton against the crown will force it and form it against the tooth 8 in accordance with the configuration of this tooth. The'flexibilit-y and resiliency of the cotton willpermit this intimate formation of the crown to be efiective, while at the'same time, this flexibility will prevent any undue pressure from injuring either the tooth or the crown, and in this way the cotton acts not only as a eans for applying pressure to the corwn but as a means of cushioning the blows or impacts to which the crown and tooth are subjected. It is found that with but several tape of the hammer the gold crown, which is made of soft flexible material. is shaped on to the tooth. The tooth and the rown are then removed from the swaging" block 11 and thecrown can, by

reason of its flexibility, be readily withdrawn from the tooth. Before taking the gold crown off the metal tooth 8, this tooth acts as means for firmly and convenientlyholding the crown without distorting it duringthe time it is'being polished. This metal tooth, which is a sort of a model of the patients tooth, may be preserved, if desired, for record" or for future use, or, being made of fusible metal, can-be readily melted for remethod whereby crowns for teeth can be very quickly and easily made with a minimumexpenditure of time and labor and in a very economical manner. The gold cap or crown can also used to place over the tooth in which it is desired to hold or retain medicine in the treatment of a nerve or sensitive part. This treatment is particularly sanitary since the tooth can be covered to hold the medicine in place. The gold caps or crowns can, of course, be soldered permanently in place after the final treatment.

l/Vhat I claim is:

1. A dental mold which comprises a plastic impression of a tooth to be crowned, a hollou shell-like matrix disposedover the impression of the tooth, and sealing material disposed around said matrix to seal the matrix in position over the impression whereby liquid metal can be poured into the matrix and the impression to form a mold for a metal tooth and a stem therefor.

2. A matrix for use in forming metal teeth, which comprises a sheet of flexible metal capable of being folded up in the form of a cylinder to be placed over the recess or impression of a tooth in a bite of plastic material.

3. A method of forming a. metal tooth which comprises forming an impression of the desired tooth in a plastic bite, placing a cylindrical matrix over this impression to seal it off from the rest of the bite, and then pouring moulten metal into the matrix and the impression to form a metal tooth having a stem and a tooth "ortion. t. The method 0 forming a metaltoo'th, which comprises forming an impression of the desired tooth in a plastic bite, placing a cylindrical matrix over the impression to seal it from the remainder of the bite, placing sealing material around the matrix to hold it in position andto seal the joint be-: tween the matrix and the impression of the tooth, and then pouring liquid metal in through the matrix into the impression to form a tooth and a stem portion thereon.

JOSEPH MICHAEL FLANIGAN. 

